1. Section of Otolaryngology—Head and Neck Surgery, Department of Surgical and Biomedical SciencesUniversity of Perugia Perugia Italy
2. Department of Otolaryngology—Head & Neck SurgeryRegina Elena National Cancer Institute Rome Italy
3. Humanitas Clinical and Research CenterRozzano (MI)
4. Department of Head and Neck SurgeryPoznan University of Medical Sciences, The Greater Poland Cancer Centre Poznan Poland
5. Department of Biology and Environmental StudiesPoznan University of Medical Sciences Poznan Poland